| Day | Date | High/Low | Forecast |
| Thu | 19th | 76/53 | Mostly sunny day with scattered high clouds. Scattered evening high clouds. |
| Fri | 20th | 70/50 | Chance of some early morning fog; Otherwise, mostly sunny day with some high clouds. Partly cloudy evening. |
| Sat | 21st | 67/50 | Chance of early morning low clouds/fog; Otherwise, partly cloudy day. Partly cloudy evening. |
| Sun | 22nd | 66/51 | Partly cloudy through the evening. |
| Mon | 23rd | 67/52 | Partly cloudy through the evening. |
Synopsis
High pressure aloft continues its dominance over the state today. However, the latest off-shore flow event in southern California is winding down (now at higher elevations only with gusts mainly below 25 mph). The surface off-shore flow was weak enough to allow areas of fog to return to the coast (Long Beach southward early today). Satellite imagery showed the fog/low clouds increasing over Santa Monica Bay. So, with a marginal, on-shore flow developing now, areas of coastal fog (dense in some locales) are likely tonight into tomorrow.
A modest shift in the Northeast Pacific jet stream will allow a series of “short waves” to bring wet weather to the Pacific Northwest states and the northern third of California (beginning Saturday…astronomically speaking, winter begins that day at 1:20 AM). The occasional wet weather should spread south in the state over time (dry periods next week less than 48 hours duration for northern California. Although some of the waves will have access to an atmospheric river, much of it will be pointed toward the Pacific Northwest. So, except for one system (slated for Monday night or Tuesday in California), the wet episodes aren’t predicted to be that significant (minor to modest amounts). The Monday night/Tuesday storm should produce a decent soaking for much of northern California (includes 1-2 feet of “wet snow” in the Sierras).
Most computer model forecasts show some wet weather reaching southern California from the beginning of the week storm (sometime Tuesday late morning or afternoon in L.A. County, if today’s model consensus is right). However, most model solutions don’t show widespread, relevant rain (snow levels staying mostly above 7000 feet). In fact, some model solutions predict less than a tenth inch in the lowlands away from the mountains (valid for areas south of Point Conception). A few model solutions show only spotty rainfall occurring (mostly trace amounts). Regardless of whether widespread wet weather reaches the Southland, dry weather should prevail for Christmas and beginning of Hanukkah.
Despite the expectation of occasional wet weather in northern California next week (right into the subsequent weekend, if today’s model consensus holds up), high pressure aloft is predicted to rear its head in the Southland at times (namely late Sunday into Monday briefly as well as late next week…possibly over the subsequent weekend too). Most of the models aren’t predicting significant Santa Ana winds, and temperatures may stay mostly around normal levels. However, I wouldn’t be surprised if warmer than normal weather develops on some days, especially late next week.
The general model consensus favors dry weather in the Southland on New Year’s Day (no surprise there). However, depending on which model solution is right, it could be a cool day (low to mid-60s in the coastal plain) or a warm day (mid to upper 70s away from the coast). By this time, even northern California may enter a dry period. I should warn as usual that much could change, weather-wise, between now and the end of 2024. So, take my outlook with a grain of salt.
Next issued forecast/synopsis should be on Monday, 6 January, 2025.
Happy holidays and wishing all a prosperous, new year!